Integration, definite

Okay, so I have this problem:
Consider the integral: where and a=1, b=2

A)Based on a graph of g''(x) in the interval [1,3], determine a suitable value of M2. (the 2 is subscript)

B)Compute the minimum number of subintervals n necessary to approximate I to within 10 (-4) using the trapezoidal rule.

C)Using the value of n found in (b) and the Module trap, find the approximate value of I
Now, I understand how to do part c, it's just a function we defined in mathematica but I'm not sure what they want for M base 2?
Regards,
Matt